An automated caller called my cell phone number and the robot said “If you are owing the IRS more than $5000, we can help! Press 1 to speak with a representative to find out how we can help. Or press 0 if you would like us to remove you from our calling list.”
And since it was my personal cell phone number, I pressed 0 (not sure if it really will blacklist my number, but it probably won't).